General wireless question

I just finished assembling a MSI WinPC and installed Opensuse 11.1. I added an Intel 3945ABG wireless card, and a 5.5dbi external antenna. I will be placing this pc in my basement acting as a file server.

I was having trouble with the wireless connection so I moved an access point closer to the WinPC (ran a cable over the floor from up to down stairs). With the access point close, wireless connects and works fine through reboots. iwlist wlan1 scan shows a signal strength of -30db. Once I am connected I can turn off that access point and the box will stay connected to a fix one I have on the 1st floor. iwlist wlan1 scan shows a signal strength of ~ -70db. If I reboot with the closer access point off wireless won’t work.

Below is the scan with the fixed access point. I always turn off SSID broadcasts and restrict what mac addresses the AP will allow. I have also tried SSID bcast on without success…

iwlist wlan1 scan
wlan1     Scan completed :
          Cell 01 - Address: 00:1C:F0:49:5E:E4
                    Frequency:2.437 GHz (Channel 6)
                    Quality=59/100  Signal level:-72 dBm  Noise level=-127 dBm
                    Encryption key:off
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra: Last beacon: 24ms ago

Two questions, 1)Is -70db usually an acceptable operating range and 2) if it is how do I trouble shoot the startup connection issue with the 1st floor (-70db)AP ?

Did some internet searching and decided to install Kismet and do a trace. With the temp AP disabled Kismet sees the permanent AP and dumps stats but still no connection. Anyone have an idea on what the problem might be or how to proceed on a resolution?